JP4567288B2 - Pump assembly - Google Patents

Abstract

A pump assembly flows pressurized engine oil to HEUI fuel injectors in a diesel engine. The assembly includes an inlet throttle valve which controls the volume of oil flowed to the pump dependent upon the difference between the pump outlet pressure and a desired outlet pressure determined by an electronic control module for the diesel engine.

Description

[0001]
(Field of Invention)
The present invention relates to a pump assembly and a pumping method for controlling the output of the pump assembly by reducing the flow rate at the inlet to the pump. The pump assembly and pumping method can be used to pressurize engine oil used in the fuel system of a hydraulic electronic unit injection (HEUI) diesel engine.
[0002]
(Description of prior art)
Diesel engines using HEUI fuel injectors are well known. In response to a signal from the electronic control module of the diesel engine, the HEUI fuel device extends the fuel plunger by the high-pressure engine oil supplied to the injector and opens the valve for a period of time during which fuel can be injected into the combustion chamber. Includes actuating solenoid.
[0003]
The HEUI injector is operated by oil drawn from a diesel engine oil pan by a diesel engine oil pump and flowing into a high pressure pump assembly driven by the diesel engine. The pump assembly pumps high pressure oil into an oil manifold or compression chamber. The manifold or compression chamber is connected to a HEUI injector. With the exception of large engines, high pressure pump assemblies typically include swashplate pumps that use axial pistons, the output of which depends on the speed of the diesel engine. Larger pumps sometimes use variable angle swashplate pumps whose output can vary independently of engine speed.
[0004]
The pump assembly pumps oil at a rate that varies with the speed of the engine. The output must be sufficient to meet the maximum flow requirements. The oil pressure in the oil manifold or compression chamber is controlled by an injection pressure regulation (IPR) valve in response to a signal received from the engine's electronic control module. The IPR valve limits the pressure of the pumped oil by returning excess high pressure oil to the engine oil pan.
[0005]
Most HEUI injection systems use a fixed output oil pump assembly that pumps oil at a speed independent of the actual instantaneous flow requirements of the engine, depending on the rotational speed of the diesel engine. Even if the pump needs to drain excess high pressure oil back into the oil pan to immediately limit the oil pressure in the manifold as required by the engine's electronic control module Always operates at full capacity. Always driving the pump assembly at full capacity requires significant power. The energy required to pump out the high pressure oil that has been released back to the oil pan is wasted and reduces the fuel economy of the diesel engine. When high pressure oil is discharged without doing useful work, energy is converted to heat. The heat of the returned oil must typically be dissipated by a heat exchanger. Therefore, the capacity of the heat exchanger needs to be increased to allow extra heat load.
[0006]
Accordingly, there is a need for an improved high pressure pump assembly and pumping method for use in HEUI diesel engines. The pump assembly needs to pump engine oil into the high pressure oil manifold or compression chamber in a variable amount sufficient to maintain the desired instantaneous pressure in the manifold without significant pumping. Return of pressurized high pressure oil to the oil pan should be minimized. The pumps in the pump assembly need to be able to pump oil with variable capacity, need to be less expensive and less complex than current HEUI pumps.
[0007]
(Summary of the Invention)
The present invention is an improved pump assembly, high pressure pump and pumping method in which the output of the pump assembly can be varied by controlling, i.e., throttling, the inlet flow to the pump assembly.
[0008]
The pump assembly is particularly useful in pressurizing oil used to operate HEUI fuel injectors for diesel engines. The improved pump assembly includes an inlet throttle valve that controls the oil inlet flow rate from the diesel engine oil pump to the high pressure pump. The inlet throttle valve throttles or reduces the amount of oil flowing into the high pressure pump in response to a signal received from the engine's electronic control module.
[0009]
The high pressure pump includes a crank that reciprocates the piston within the bore. Oil supplied to the high pressure pump through the inlet throttle valve flows into the crank chamber and into the bore during the return stroke, is compressed during the pumping stroke, and is pumped through the outlet poppet valve to the high pressure manifold. When the inlet throttle is fully opened, enough oil flows into the crank chamber to fill the pumping chamber during the return stroke, and the oil is pumped into the manifold at the full pump capacity. When the inlet throttle valve is partially closed, a reduced amount of oil flows into the crank chamber, partially fills the crank chamber and is pumped below the full capacity of the pump.
[0010]
The inlet throttle valve has a main stage valve for flowing pressurized oil from the outlet of the pump to the oil pan when it is necessary to limit the pressure in the manifold, and an electrically modulated pilot stage valve Controlled by an injection pressure adjusting valve.
[0011]
The pilot stage valve includes a solenoid that is modulated by a signal from an electronic control module to inhibit the pilot flow of oil from the pump outlet. To reach the pilot stage, oil from the pump outlet must pass through a restraining orifice in the main stage spool, thereby adjusting the spool against the spring closure force. From the pilot stage, the pilot flow passes through the downstream suppression orifice and then returns to the engine oil pan with the discharge flow from the main stage of the injection pressure regulating valve. The pressure of the oil in the room between the pilot stage and the downstream suppression orifice is detected by the flow rate of the pilot flow. The chamber between the pilot stage and the downstream restrictor orifice communicates with the spool end of the inlet throttle valve and acts on the spool area to resist the inlet pressure acting on the spring and spool area. The valve spool is moved in the closing direction to control the flow of oil to the crank chamber, that is, generate a force to squeeze.
[0012]
By controlling, ie throttling, the oil flow into the crankcase, the flow rate of the high pressure oil pumped from the outlet into the high pressure manifold by the pump is controlled as necessary to maintain the desired pressure in the manifold. The pump assembly will flow a sufficient amount of oil to maintain the desired pressure in the manifold. Pump assemblies rarely meet flow requirements while pumping in full volume. Less power is required to pump oil with the HEUI pump. The fuel efficiency of the diesel engine is improved by reducing the power required to drive the high-pressure pump. The need to cool the oil in the oil pan is also reduced.
[0013]
The pump assembly includes two banks 90 degrees apart with two single high pressure check valve piston pumps in each bank. Each pump includes a piston in the bore and a spring in the bore that resiliently presses the piston against the slipper socket and holds the slipper against the eccentric member of the crank. The eccentric member is offset 180 degrees so that the pistons in the four pumps move through pumping strokes spaced 90 degrees apart to provide an evenly spaced high pressure oil pumping cycle during every 360 degree rotation of the crank. It can be timed to generate pulses during the injection process.
[0014]
Each high pressure piston pump includes a bore extending toward the crankshaft axis, a piston in the bore, and a check valve assembly attached to the outer end of the bore and connected to the high pressure passage. The check valve assembly is attached to the bore by press-fitting a sleeve into the cylindrical outer end of the bore and then press-fitting a plug into the sleeve, with a high pressure between the plug, the sleeve and the bore. The connection part is formed. The check valve assembly can be installed without threading the bore and without the complex machining and fouling characteristic of a threaded plug. The valve seat of the check valve is held on the sleeve by a tapered engagement that presses the sleeve radially outward to improve sealing and increase the holding force of the sleeve.
[0015]
Other objects and features of the present invention will become apparent as the following description proceeds, particularly when read in conjunction with the accompanying drawings illustrating the invention.
[0016]
(Description of preferred embodiment)
The inlet throttle control pump assembly 10 is mounted on a diesel engine, typically a diesel engine used to drive a road vehicle, and supplies high pressure engine oil to a solenoid operated fuel injector 12. The input gear 14 of the pump assembly 10 is rotated by the engine to drive the pump assembly. Engine lubricating oil is drawn from the oil pan 16 by the engine lubricating oil pump 18 and is flowed to start the reservoir 19 and the inlet port 20 of the pump assembly. The oil pump also flows engine oil through piping 260 to the engine bearings and cooling injectors. The reservoir 19 is located above the pump assembly 10.
[0017]
The pump assembly 10 pushes away the oil and flows the oil from the outlet port 22 along the flow path 24 to the injector 12. The flow path 24 may include a manifold attached to the diesel engine. A high pressure compression chamber 26 is connected to the flow path 24. The chamber may be located outside the diesel engine. Alternatively, the oil manifold may have sufficient volume to eliminate the need for an external chamber.
[0018]
The pump assembly 10 includes a cast iron body 28 having a mounting surface 30 with mounting holes 32 extending through the mounting surface 30 to facilitate bolting the pump of the assembly 10 to a diesel engine. . A mounting collar 34 extends outwardly from the surface 30 into a cylindrical opening formed in the mounting surface on the diesel engine, and meshes the gear 14 with the engine gear rotated by the engine crankshaft. ing. An O-ring seal in the collar 34 seals the engine opening.
[0019]
A crank chamber 36 is formed in the lower portion of the body 28 and extends between the interior of the collar 34 and the opposite closed end. A crankshaft 40 is fitted in the crank chamber 36. The journal at the inner end of the crankshaft is supported by a sleeve bearing 42 mounted on the body 28 near the blind end of the crankcase. The journal at the opposite end of the crankshaft is supported by a sleeve bearing 44 supported by a bearing block 46. The block 46 is press-fitted into the collar 34. Shaft seal 48 is carried at the outer end of block 46 and includes a lip that engages a cylindrical surface at the outer end of the crankshaft. The lip extends away from the crankcase 36 to allow engine oil to flow from the annular space 49 behind the seal through the seal and into the diesel engine.
[0020]
While the pump assembly 10 is operating, engine oil flows into the crankcase and contacts the inner surface of the bearing between the crank journal and the sleeve bearings 42,44. If the pressure in the crank chamber is greater than the pressure at the distal end of the bearing surface between the journal and the sleeve bearing, a small oil flow for lubrication will flow through the bearing surface in the end chamber 66 and the annular space 49. Ooze out. This oil flow from the crankcase lubricates the sleeve bearing. The oil collected in the chamber 66 flows through the passage 64 to the space 49 where it collects with oil from other bearings. Oil in the space 49 lifts the lip seal 48 and flows back from the pump assembly to the oil pan of the diesel engine. Two sleeve bearings 44 and 46 form an effective pressure seal for the crank chamber 36, the lip of the shaft seal 46 faces outward on the crankshaft, and oil can flow out of the space 49 outward. So that it can be lifted. The position of the shaft seal 48 is opposite to the position of the normal shaft seal which usually has an inwardly directed lip to prevent outward flow.
[0021]
While throttled at the inlet, the oil flow into the crankcase decreases and the crankcase pressure can drop below the pressure in the diesel engine. In this case, the oil can ooze out from the space 49 and the end chamber 66 into the crank chamber. The exuding flow of oil in or out through the bearing lubricates the bearing but does not affect the operation of the pump.
[0022]
While the oil flow into the crank chamber is throttled at the inlet, the pressure in the crank chamber can drop below the pressure in the diesel engine. This is because the pump sucks the vacuum in the crank chamber.
[0023]
A screw-engageable fixture 50 secures the gear 14 at the end of the crankshaft extending outwardly from the bearing block.
[0024]
The crankshaft 40 has two axially spaced cylindrical eccentric members 52 and 54 that are separated from and joined by a large-diameter disk 56 located on the axis of the crank. The disc reinforces the crankshaft. Each eccentric member 52, 54 is provided with a cutout slot 58 located between adjacent sides of the eccentric member and extending about 130 degrees around the periphery of the eccentric member. A passage 60 extends from the bottom of the slot 58 to two intersecting access passages 62 extending parallel to the axis of the crankshaft and extending through the eccentric member and the disk 56. Cylindrical eccentric members 52 and 54 are oriented 180 degrees out of phase on the crankshaft, so that passage 62 for eccentric member 52 crosses the crankshaft axis from passage 62 for eccentric member 54. It is located in the diameter direction. See FIG.
[0025]
An axial passage 64 extends over the length of the crankshaft. At the inner end of the crankshaft, the passage 64 is open to an end chamber 66 formed in the closed end 38 of the crank chamber. Crossing passage 68 communicates with the outer end of passage 64 by an annular space 49 behind seal 48.
[0026]
Pump assembly 10 includes four high pressure check valve piston pumps 74 disposed in two 90 degree spaced banks 70 and 72. Each bank has two piston A pump 74 is included. As shown in FIG. 3, bank 70 extends to the left of the crankshaft and bank 72 extends above the crankshaft so that the pump assembly has a Vee-4 structure. One in each bank piston The pump 74 is driven in alignment with the eccentric member 52, and the other pump in each bank is driven in alignment with the eccentric member 54. The four check valve pumps are identical.
[0027]
Each check valve piston pump 74 includes a piston bore 76 formed in one of the banks and extending perpendicular to the axis of the crankshaft. A hollow cylindrical piston 78 slides into the inner end of the bore 76. The piston has a spherical inner end 80 adjacent to the crankshaft. The inner end 80 is fitted in a spherical recess of a slipper socket 82 located between a piston and an eccentric member for operating a pump. The concave surface inside the slipper socket is cylindrical and coincides with the surface of the adjacent cylindrical eccentric member. The central passage 84 and the slipper passage 86 at the spherical end of the piston communicate with the surface of the eccentric member by a variable volume pumping chamber 88 in the piston 78 and bore 76. The variable volume portion of the pumping chamber is located in the bore 76.
[0028]
A check valve assembly 90 is located at the outer end of each piston bore 76. Each assembly 90 includes a sleeve 92 that is closely fitted to the end of the bore 76. A cylindrical seat 94 is fitted to the lower end of the sleeve. A plug 96 is fitted to the sleeve and closes the outer end of the bore 76. A poppet disc or valve member 98 is held against the outer end of the seat 94 by a poppet spring 100 normally fitted to a plug 96. A central boss 99 protrudes above the valve member 98 and is fitted to the spring 100.
[0029]
A piston spring 102 is fitted to each piston 78 and extends between the spherical inner end of the piston 78 and the seat 94. The spring 102 holds the piston against the pump slipper 82 and the slipper against the eccentric members 52 and 54. When the crankshaft 40 is rotated, the slot 58 on the surface of the eccentric member is engaged with or removed from the passage 86 of the slipper so that the engine oil can flow from the crank chamber into the pumping chamber 88 without being blocked. To do. Further, when the crankshaft rotates, the piston 78 is moved up and down in the bore 76 to pump up oil through the check valve. During rotation of the crankshaft, the piston spring 102 holds the piston against the slipper and the slipper against the eccentric member, while the slipper vibrates at the spherical end of the piston.
[0030]
The diesel engine rotates the crankshaft 40 in the direction of the arrow shown in FIGS. 3, 4, and 5. FIG. 4 shows the position of the piston 78 in the bank 72 when fully extended into the bore 76 at the end of the pumping stroke. As the crank rotates further, the spring 102 and the internal pressure 78 Is moved away from the fully extended position. Therefore, the trapped and pressurized oil is recovered, and the pressure of the trapped oil is reduced. As the crank continues to rotate, the slot 58 is moved into communication with the passage 86 in the slipper socket 82 so that oil can flow into the pumping chamber 86 which is open during the piston return stroke. FIG. 5 shows an unobstructed return stroke between the slot 58 and the pumping chamber of the pump 74 in the bank 70.
[0031]
The inlet port 20 is open into an inlet throttle valve 104 located in the body 28. See FIG. The valve 104 passes through the passage 110 from the oil pump 18 to the crank chamber 36, and piston By restricting the flow of oil flowing into the pump 74, piston The amount of engine oil pumped out by the pump 74 is controlled.
[0032]
The inlet throttle valve 104 includes a bore or passage 106 that extends into the body from the mounting surface 30 to the closed end 108. An oil inlet passage 110 surrounds the center of the bore 106 and allows the bore to communicate with the crank chamber 36. See FIG. The hollow cylindrical spool 112 provides a tight sliding fit within the bore, allowing the spool to move along the bore. The outer end 114 of the spool is open and the inner end 116 is closed to form a piston. A cylindrical wall extends between the ends of the spool. A retainer 118 is fitted to the outer end of the bore 106. An inlet throttle valve spring 120 is clamped between the ring 118 and the inner end 116 of the spool to urge the spool toward the closed end 108 of the bore. A positioning post 122 extends inwardly from the closed end of the spool toward the end of the bore. A chamber 125 surrounds the post 122 at the closed end of the bore. As will be described below, the passage 124 communicates the pressure regulating valve 192 of the injector with the chamber 125 at the inner end of the bore 106. Post 122 keeps spool 122 from closing passage 124. The closed end 116 of the spool prevents flow between the chamber 125 and the interior of the spool. The spool always extends through the passage 110.
[0033]
As shown in FIGS. 13 and 14, four large-diameter flow ports 128 pass through the wall of the spool near the open end 114. Four pairs of diametrically opposed flow control openings 130-136 offset in the axial direction are formed through the spool wall at a short distance inward from the flow port 128. A small-diameter flow control opening 130a is positioned opposite to the small-diameter flow port 130b in the diametrical direction. As indicated by line 138, the outer edge of opening 130 a is located at line 138 at the inner edge of opening 128. The opening 130b is shifted from the opening 130a inward by a short distance. The transition difference may be slightly larger than ¼ of the diameter of the opening. A second set of small diameter diametrically opposed openings 132a and 132b are formed through the spool through the spool. The opening 132a is positioned inward by the same distance from the opening 130b, and the opening 132b is positioned slightly inwardly slightly larger than ¼ of the diameter of the opening 132a. A third set of small diameter diametrically opposed openings 134a and 134b are formed through the spool, the opening 134a being located slightly inwardly of the opening 132b, slightly larger than ¼ of the diameter of the opening, and opposed small diameters. The opening 134b is slightly larger than ¼ of the diameter of the opening and is located inward from the opening 134a. Similarly, the small diameter flow passage 136a is positioned inwardly from the opening 134b slightly larger than ¼ of the diameter of the opening, and the diametrically opposed small diameter flow opening 136b is slightly smaller than ¼ of the diameter of the opening. It is located inward from the large and small-diameter opening 136a.
[0034]
During the opening and closing movement of the spool 112 within the bore 106, the flow ports 128-136 pass through the inlet passage 110. During the initial closing movement of the spool from the fully open position shown in FIG. 12, the large flow port 128 is rapidly closed. Further closing movement causes the small diameter flow ports 130a-134a and 134b-136b to partially pass through the oil inlet passage 110, reducing the area of the opening through which oil flows to the crank chamber. The movement of the spool 104 stops when it contacts the retainer 118 to minimize the flow through the pump for cooling and lubrication. The overlapping position of the small-diameter channels ensures that the flow opening becomes small smoothly.
[0035]
Opposing pairs of passages 130a, 130b; 132a, 132b; 134a, 134b; 136a, 136b reduce the load or hysteresis on the spool as it moves back and forth within the bore 106. Each of the pair of openings is diametrically opposed and is opened or closed except when the opening intersects the edge of the oil inlet passage 110. Slightly axially offset pairs of apertures are diametrically opposed to effectively balance the radial pressure forces and reduce the restraint or hysteresis during spool movement. Reducing the constraint or hysteresis ensures that the spool moves freely and quickly along the bore in response to the differential pressure across the inner end 116. The opening in the passage 110 surrounds the spool 112 and helps reduce hysteresis. Circumferentially spaced and opposed openings 128 also help reduce hysteresis.
[0036]
Constraints or hysteresis are further reduced by positioning adjacent pairs of diametrically opposed flow ports as far apart as possible in the circumferential direction. For example, as shown in FIG. 14a, openings 132a and 132b are located 90 degrees relative to openings 130a and 130b, and openings 136a and 136b are located 90 degrees relative to openings 134a and 134b. . The openings 132a and 132b are necessarily located at 45 degrees with respect to the openings 134a and 134b. Further, all the openings designated by “a” are located on one side of the spool, and all the openings designated by “b” are located on the other side of the spool valve. Such an arrangement reduces constraints and hysteresis by ensuring that the lateral loads applied to the spool are balanced and offset relative to each other as the small diameter channel opens and closes.
[0037]
In one valve 104, the bore 106 has a diameter of 19.05 millimeters (0.75 inch) and the axial length of the spool is approximately 41.91 millimeters (1.65. Inch). The large diameter flow ports 126 have a diameter of 7.92 millimeters (0.312 inches), and the small diameter flow ports 132a-136b each have a diameter of 2.39 millimeters (0.094 inches). The small diameter flow port, as described above, is offset about 0.64 millimeters (0.025 inch) relative to the adjacent opening, slightly more than 1/4 of the diameter of the opening in the axial direction.
[0038]
When the engine is stopped, the valve spool 112 is held against the closed end 108 of the bore by the spring 120 as shown in FIG. 12, and the large diameter opening 128 and some small diameter passage open to the inlet passage 110. During start-up of the diesel engine, the electric starter rotates the engine crankshaft and auxiliary elements including the oil pump 18 and the pump assembly 10 relatively slowly. To start the engine, the pressure of the oil in the flow path 24 is increased to a level high enough to start the injector 12 even though the speed of the pump 10 is slow and the capacity is correspondingly limited. The pump 10 needs to provide a flow rate for this purpose. At this time, the inlet throttle valve is fully opened, and the passage 128 opens to the passage 110. Oil from the oil pump 18 flows into the crank chamber with minimal obstruction and is pumped into the passage 24.
[0039]
As the engine starts and increases the oil pressure in passages 156 and 232, the rotational speed of the diesel engine increases. As detected by the current to solenoid 220, when the pressure reaches the desired level, the pilot relief valve is opened, allowing oil to flow into passage 124 and chamber 125, and spool 112 to the left from the position shown in FIG. To the operating position where the oil from the pump 18 flows into the crankcase via the small diameter passages 132-136 open into the passage 110. As the pressure in the chamber 125 further increases, the small diameter passages 132-134a pass through the inlet opening 110 and the passages 134b, 136a, 136b are partially open, further to the left of the spool. Move to a partially closed position where a minimum amount of oil is allowed to enter.
[0040]
Movement of the spool 112 by pressure causes the flow control openings, or holes 128-134a, to pass through the inlet passage 110, reducing the flow area of the cross section of the valve 104 and reducing the amount of oil flowing into the crank chamber. That is, squeeze.
[0041]
The oil flowing into the crank chamber enters the outlet opening 150 passing through the sleeve 92. piston 74 is pumped out. Bank 70 piston The opening 150 of the pump 74 communicates the valve space above the poppet disc with the high pressure outlet passage 152. Bank 72 piston The outlet opening 150 of the pump 74 communicates the space above the poppet disk with the high pressure outlet passage 154. The inclined high pressure outlet passage 156 is connected to passages 152 and 154 as shown in FIG.
[0042]
A supply ball check valve 158 is located between the passage 156 and the passage 160 opened to the crank chamber 36. See FIG. The gravity and pressure of oil in the outlet passage normally keeps the valve 158 closed. A spring 162 is fitted in the cross passage above the check valve to prevent the ball of the valve 158 from slipping. When the diesel engine is stopped and cooled, the pressure drops and the oil in the high pressure flow path and manifold 24 is cooled and contracts. The engine crankcase pressure acting on the fluid in the reservoir 19 lifts the ball of the valve 158 and supplies replenishment oil from the crank chamber to the high pressure flow path to prevent the formation of bubbles in the passage.
[0043]
A high pressure mechanical relief valve 168 shown in FIG. 8 is positioned between the banks 70 and 72 and extends parallel to the axis of the crankshaft. Valve 168 extends from mounting surface 30 to high pressure outlet passage 156. A valve seat 172 is held against the step 173 of the passage 170 by a press-fitted sleeve 175. The step faces away from the passage 156. The valve member 174 normally engages the seat to close the valve. A retainer sleeve 176 is press-fitted into the passage 170 at the surface 30. The spring 178 is held between the retainer and the valve member 174 and is held against the seat at a high pressure so that the valve 168 is normally closed. When the pump assembly 10 is attached to a diesel engine, the outlet opening 180 in the sleeve 176 is aligned with the passage leading to the engine oil pan. An O-ring seal is fitted in the groove 182 to prevent leakage. When the mechanical relief valve 168 is opened, high pressure oil flows from the outlet passage 156 back to the engine oil pan. Valve 168 has a cracking pressure of about 315 kilograms per square centimeter (4,500 pounds per square inch).
[0044]
The cross-sectional area between the sleeve 175 and the valve member 174 is selected so that the pressurized oil acts on the cross-sectional area of the valve member 174 when the valve is opened. Increasing the flow rate through the relief valve requires an increase in the displacement of the valve member 174 from the valve seat 172, and thus requires more force as the spring 178 deflects against its spring gradient. Suppression of the flow between the valve member 174 and the sleeve 175 is selected such that the auxiliary force from the increased flow is offset by the increased spring force, and the relief pressure is relatively independent of the flow through the relief valve. is doing.
[0045]
A high pressure outlet passage 156 opens into a stepped hole 166 that extends into the body 28 above the inlet throttle valve 104 and transverse to the axis of the crankshaft 40. See FIG. A discharge passage 190 extends from the large diameter portion of the stepped hole 166 to the chamber 66. See FIG.
[0046]
The injection pressure adjustment (IPR) valve 192 is attached to the outer portion of the stepped bore 166 with a screw. Valve 192 is an electrically modulated, two-stage relief valve manufactured by Navistar of International Corporation of Melrose Park, Illinois and FASCO of Shelby, NC, part number 18255249C91 (Navistar International Transportation Corporation of Melrose Park, Illinois Part No. 18255249C91).
[0047]
The IPR valve 192 shown in FIG. 9 has an elongated hollow main body portion 193 attached to a large diameter portion of a stepped bore 166 with a screw and a base portion 196 at the outer end of the main body portion 193. The IPR valve includes a main stage mechanical relief valve 194 located at the inner end of the main body 193 and an electrically modulated relief valve 195 of the pilot stage located at the outer end of the main body 193. The body 193 holds the spring 162 in place. An O-ring and backup ring 198 seals the inner end of the body 193 against the small diameter portion of the bore. A cylindrical valve seat 200 is attached to the inside of the main body 193 near the base 196 and includes an axial flow passage 202.
[0048]
The main stage valve 194 includes a cylindrical spool 204 that is slidably attached to the body 193 and has an axial passage that includes a restraining portion 206. A spring 208 held between the valve seat 200 and the spool 204 urges the spool toward the inner end of the bore 166 to the position shown in FIG. The spring holds the spool against a stop member (not shown) in the main body 193. Oil from the high pressure outlet passage 156 flows into the inner end of the main body 193.
[0049]
The collar 212 is fixed to the main body 193, and a large diameter portion of the hole 166 is divided into an inner cylindrical chamber 214 extending from the step to the collar and an outer cylindrical chamber 216 extending from the collar to the base 196. It is separated. A narrow collar 218 separates the collar from the base. A small diameter outflow passage 219 passes through the collar 212 and communicates with the chambers 214 and 216. See FIG. 9A.
[0050]
If transient pressure occurs in the high pressure passage, the oil pressure causes the spool 204 of the main stage valve 194 to move to the left, ie, toward the seat 200, against the spring 208. The movement of the spool is sufficient to pass the end of the spool away from the spring through a number of discharge passages 210 penetrating the body portion 193. High pressure oil then flows through passage 210 into chamber 214, through discharge passage 190 to chamber 66, and then back to the diesel engine oil pan as described above.
[0051]
Pilot stage valve 195 includes a solenoid 220 at base 196. The solenoid surrounds the armature 222 that is axially aligned with the base 196. The left end of the armature engages with a holding block 224 held by a tube fixed to the main body 193. A solenoid lead 226 is connected to the electronic control module of the diesel engine. A valve pin 228 in contact with the armature 222 extends toward the flow path 202 of the valve seat 200 and engages the seat to close the passage when the armature is biased toward the seat by the solenoid 220. It has a leading end with a mark.
[0052]
High pressure oil from passage 156 flows through restraint 206, into body portion 193, and through passage 202 in seat 200 to the end closed by valve pin 228. The electronic control module sends a current signal to the solenoid, changes the pin force relative to the valve seat, and is located on the screw that attaches the IPR valve to the body 28 and includes a passage 202 including a slot 230 leading to the chamber 216, and the IPR valve Controls oil flow through the internal passage. Oil from chamber 216 flows through restraint 219 to chamber 214 and then to the engine oil pan as described above. Chamber 216 is connected to chamber 125 by passage 124 so that oil in chamber 216 pressurizes oil in chamber 125 of the inlet throttle valve. The IPR valve 192 is shown in detail in FIG. 9 and schematically shown in FIGS.
[0053]
FIGS. 16 and 17 illustrate how the check valve 90 is assembled at the outer end of the piston bore 76 during manufacture of the pump assembly 10. First, the piston 78 is put into the opened bore 76, and the spring 102 is fitted to the piston. The piston engages with the slipper 82 of the eccentric members 52 and 54. Next, the sleeve 92 that is tightly fitted in the bore 76 is press-fitted into the bore.
[0054]
As shown in FIG. 17, the inner surface 91 of the inner wall of the sleeve 92 is tapered inward to increase the thickness of the sleeve. The outer wall of the seat 94 is also correspondingly tapered outward. A seat 94 is inserted into the sleeve and the end of the sleeve and the tapered surface at the seat engage each other. The seat 94 is then driven to the position shown in FIG. 16 to form a tight wedge connection of the sleeve. Such a connection deforms the sleeve relative to the bore wall and strengthens the connection between the sleeve and the bore 76. A small diameter collar 101 at the inner end of the seat extends to the center of the spring 102 to position the spring radially in the pumping chamber 88.
[0055]
Next, the poppet disc 98 is positioned on the spring 100, the spring is fitted into the plug 96, and the plug 96 is driven into the open outer end of the sleeve 92. Driving the plug 96 into the sleeve creates a strong closure connection between the plug and the sleeve, strengthening the bond between the sleeve and the wall of the bore 76. A circular boss 99 at the top of the poppet disc 98 extends into the spring 100 so that the spring holds the poppet disc 98 in place with respect to the seat 94.
[0056]
FIG. 18 shows a check valve assembly 90 instead of piston An alternative check valve assembly 240 that may be used in the pump 74 is shown. Assembly 240 includes a sleeve 242 that is driven into the outer end of bore 76 as described above. The sleeve 242 includes a tapered lower end that receives the seat 244 by a tapered drive connection between the seat and the sleeve as shown in FIG. The outer end 246 of the sleeve extends above the top of the body 28 when the sleeve is fully positioned in the bore 76.
[0057]
The plug 248 of the assembly 240 is longer than the plug 96 and includes a circumferential cut-out 250 that is inclined at the outer end of the plug protruding from the body 28. The internal opening of the plug 248 is the same depth as the corresponding opening of the plug 96.
[0058]
After the sleeve 242 and seat 244 are pushed into the passage, Poppet Like the disc 98, a poppet disc 252 is mounted on the spring 254 like the spring 100, the outer end of the spring extends into the hole in the plug 248, and the plug is pushed into the sleeve to the position shown in FIG. The cut-off groove 250 is positioned above the surface of the main body 28. The upper end of the sleeve is then deformed into a groove that is cut down to provide a strong connection that closes the outer end of the hole.
[0059]
The gear 14 rotates the crankshaft 40 in the direction of the arrow 256 shown in FIGS. 3, 4, and 5, that is, counterclockwise as viewed from the mounting surface 30. The eccentric members 52 and 54 are rotated by the rotation of the crankshaft, and the piston 78 is reciprocated in the bore 76. Each high pressure piston In the pump 74, as the piston reciprocates in the bore 76, the spring 102 holds the spherical inner end of the piston 78 against the slipper 82 and abuts the slipper against the rotating eccentric member. During the return movement of the piston toward the crankshaft, that is, the suction movement, the inlet passage from the crank chamber 36 to the pumping chamber 88 is not blocked. There is no check valve in the inlet passage. The unobstructed inlet passage extends through passage 62, passage 60, slot 58 and slipper passages 86 and 84, and the inner end of piston 78. An unobstructed inlet passage allows engine oil in the crankcase to freely flow into the pumping chamber during the return stroke. After the piston 78 has returned sufficiently so that the oil trapped near the beginning of the return stroke can expand, the inlet passage is opened and closed at the end of the return stroke.
[0060]
4 shows the bank 72 at the top dead center. piston A pump 74 is shown. Oil in chamber 88 is poppet valve Element Flow through 98 and the valve is closed. The closed pumping chamber 88 remains filled with high pressure oil. The passage 86 in the slipper 82 is closed, and the crank rotates 18 degrees beyond top dead center and remains closed until the slot 58 communicates with the passage 86. While rotating 18 degrees from top dead center, piston 78 moves 2 percent of the return stroke from top dead center, and the pumping chamber and the compressed oil in the chamber recover most of the compression energy in the fluid. Inflates like so. The recovered energy assists the rotation of the crankshaft. When the pumping chamber opens to the crank chamber, the fluid pressure in the pumping chamber is recovered to reduce the fluid pressure in the chamber so that the fluid flows outward into the crankshaft slot 58 at high speed. Absent. Recapturing the energy of the compressed fluid in the pumping chamber improves the overall efficiency of the pump by about 2 percent.
[0061]
If the crank slot moved over the opening 86, i.e. just after top dead center, the high pressure fluid in the pumping chamber flows into the slot through the opening at high speed. This speed is sufficient to risk damaging the surfaces of passages 84 and 86 and slot 58 with that flow. By opening the pumping chamber at about 18 degrees after top dead center, it is possible to reduce the pressure in the pumping chamber before opening, eliminating the damage caused by the high flow rate on the face of the pump. The pumping chamber opens early enough with a return stroke to fill before closing at bottom dead center.
[0062]
It is important that the inlet passage is not obstructed during cold start. While the passage is open, engine oil in the crankcase, which can be cold and viscous, flows into the pumping chamber during the return stroke as the volume of the pumping chamber increases. The circumferential length of the slot 58 and the diameter of the passage 86 are adjusted so that the piston pumping chamber opens to receive oil from the crank chamber during substantially all of the return stroke.
[0063]
The pump poppet valve is held closed by the spring 100 and high pressure oil in the outlet passage during the return stroke. In FIG. piston Pump 74 is at the bottom of the return stroke. The oil flows into the pumping chamber 88 and the inlet passage communicating with the crank chamber is closed at the bottom dead center. Bank 70 piston The pump 74 moves through part of its return stroke, and the inlet passage to the pumping chamber 88 communicates with the crank chamber unobstructed. Oil can flow from the crank chamber directly into the slot 58 on either side of the slipper 82 or through the passages 60 and 62 into the slot.
[0064]
The unobstructed inlet passage is open to allow oil to flow into the pump chamber during the entire return stroke of the piston, except for the first two percent of the stroke following top dead center. Essentially, an unobstructed passage to the pumping chamber is provided during the entire return stroke to increase the capacity of the pump and facilitate the flow of cold viscous oil into the pumping chamber during start-up.
[0065]
After each piston has completed its return stroke, the pumping chamber is filled or partially filled with oil from chamber 36, depending on the amount of oil that has flowed to the crank through inlet throttle valve 104. . The crankshaft then rotates to move the piston outward through the pumping stroke. During the pumping stroke, the eccentric member slot 58 driving the piston is remote from the pump slipper passage 86 and the inlet passage leading to the pumping chamber is closed at the eccentric member. When the piston moves outward by the eccentric member, the volume of the pumping chamber is reduced and the pressure of oil in the chamber is increased. The cavity in the partially oil-filled chamber decreases in volume and then collapses as pressure increases. When the oil pressure in the chamber exceeds the oil pressure on the high pressure side of the poppet disc 98, the disc lifts from the seat 94 and the pumping chamber oil is released into the high pressure passage through the opening in the seat. Pumping continues until the piston reaches top dead center at the end of the pumping stroke and begins a return stroke. At this time, the spring 100 closes the poppet valve, and the pressure in the pumping chamber decreases below the oil pressure in the high pressure passage.
[0066]
During operation of the pump assembly 10, the sleeve bearings 42 and 44 are lubricated by the oil spill from the crankcase 36. The oil flowing through the bearing 44 collects in the space 49 behind the seal 48, lifts the seal, passes through the seal, and is discharged to the oil pan of the diesel engine. Oil flowing through the bearing 42 passes through the passage 190 from the pilot and main stage of the IPR valve and is collected in the end chamber 66 together with the oil flowing into the end chamber 66. The oil in the chamber 66 passes through the cross passage 68 and through the crankshaft axial hole 64, lifts and passes the seal 48, and then is discharged to the oil pan of the diesel engine. When the pressure in the crank chamber 36 is below atmospheric pressure, the bearings 42 and 44 can be lubricated by the oil flowing into the chamber 66 with the inlet throttled.
[0067]
FIG. 15 shows a hydraulic circuit of the pump assembly 10. The components of the injection pressure regulating valve 192 are indicated by dotted rectangles on the right side of the figure. The remaining elements of the pump assembly 10 are shown as dotted rectangles on the left side of the figure.
[0068]
The diesel engine oil pump 18 flows engine oil from the oil pan 16 to the starting reservoir 19, the inlet port 20, and via piping 260 to the diesel engine bearings and cooling injectors. The starting reservoir 19 is located above the pump assembly 10. The reservoir includes an outflow orifice 21 at the top thereof. When the reservoir is empty, the outlet orifice vents air from the sealed reservoir to the engine crankcase, allowing the pump 18 to fill the reservoir with engine oil. During engine operation, the reservoir 19 is filled with engine oil and the outlet orifice causes a small flow of oil to leak into the oil pan. When the engine is stopped, the oil pressure in the reservoir 19 decreases and the outflow orifice allows the oil from the reservoir to flow through the inlet port 20 into the crank chamber 36 by gravity and suction with the pressure at the engine crankcase. Like that. Thus, before the oil pump 18 draws oil from the oil pan 16 and flows the oil to the pump assembly, the oil from the reservoir 19 is initially pumped into the injector during crank operation and start-up of the diesel engine. Available.
[0069]
Oil flows from port 20 to inlet throttle valve 104. The oil from the inlet throttle valve 104 is supplied to the four pumps indicated by the pump assembly 241. piston Flows to pump 74. Oil compressed by rotation of the pump crankshaft 40 flows from the assembly 241 to the high pressure outlet passage 156 and through the high pressure outlet port to the flow path 24 and the fuel injector 12.
[0070]
High pressure outlet passage 156 is connected to the inlet of pump assembly 241 by supply ball check valve 158 and passage 160. The high pressure outlet line 156 is connected to a high pressure mechanical relief valve 168 that, when opened, returns high pressure oil to the oil pan 16 to limit the maximum pressure.
[0071]
The two-stage injection pressure regulating valve 192 includes a main stage mechanical relief valve 194 and a pilot stage electrically modulated relief valve 195. The mechanical pressure relief valve 194 is shown in the closed position in FIG. In the closed position, the spool 204 closes the discharge passage 210. When the spool shown in FIG. 9 moves to the left, the passage 210 is opened, high-pressure oil flows from the passage 156 to the passage 210 and the passage 190, and then returns to the oil pan of the diesel engine as described above.
[0072]
Pressurized oil in passage 156 urges spool 204 of valve 194 toward the open position and is resisted by fluid pressure in spring 208 and IPR valve chamber 232. The chamber 232 is connected to the high-pressure passage 156 via an internal flow restricting portion 206 in the spool.
[0073]
The pressure of the oil in the chamber 232 acts over the area of the hole in the seat 200 at one end of the valve pin 228 of the pilot stage of the valve 195, pressing the pin toward the open position. The solenoid 220 presses the pin against the seat 200 toward the closed position. Pilot flow of oil from valve 195 flows through slot 230 in the screw mounting base 196 at the outer portion of hole 166 and flows to chamber 216, through orifice 219 to chamber 214, and then to the engine oil pan. . Pressurized oil in the chamber 216 is directed by the passage 124 to the chamber 125 of the inlet throttle valve 104 and represses the spool 112 in the direction away from the closed end 108 of the bore 106, as shown in FIG. The spring 120 and the oil pressure from the pump 18 urge the spool in the opposite direction. The position of the spool is determined by the resulting force balance.
[0074]
The operation of the inlet throttling control pump assembly 10 will now be described.
[0075]
At the start of the diesel engine, the start reservoir 19 contains enough oil to supply the pump 10 until the oil is replenished by the diesel engine oil pump. The outlet orifice 21 may allow the reservoir to be at the crankcase pressure of the engine. The oil can be cold and viscous. The high pressure manifold 24 is full of low pressure oil. The spring of the inlet throttle valve 104 extends the spool 112 to the fully open position shown in FIG.
[0076]
When the starter motor for the diesel engine is operated, the gear 14 and the crankshaft 40 are rotated. The engine oil pump 18 also rotates, but does not immediately flow oil into the pump assembly.
[0077]
During start-up, gravity and engine crankcase pressure cause engine oil to flow from reservoir 19 to port 20 through the open inlet throttle valve and into crank chamber 36. Despite its viscosity, the oil in the crank chamber is freely sucked into the pumping chamber 88 by the vacuum via the inlet passage where the crankshaft is not blocked, the slipper, and the inner end of the piston 78. During startup, the pump assembly causes oil to flow into the manifold 24. The pressure increases to the starting pressure and activates the injector 12. The starting pressure may be 70 kilograms per square centimeter (1,000 pounds per square inch). The reservoir 19 has a volume sufficient to supply oil to the pump assembly until the oil pump draws oil and flows it to the pump assembly. During start-up and initial pressurization of manifold 24, valves 194 and 195 are closed.
[0078]
When the diesel engine is operating, the pump assembly 10 maintains the oil pressure in the manifold 24 in response to a current signal from the electronic control module to the solenoid 220. The signal is proportional to the desired instantaneous pressure in the high pressure outlet passage and manifold 24. The pump assembly 10 pumps a slightly larger amount of oil than is necessary to maintain the desired instantaneous pressure in the manifold 24. If the pressure in the manifold 24 needs to be quickly reduced, excess high pressure oil is returned to the oil pan via valve 194. For example, if the engine torque command decreases rapidly, a significant flow rate must be returned to the oil pan via the valve 194.
[0079]
During the operation of the engine, the flow of the high-pressure oil flowing out passes through the suppression unit 206, is reduced in pressure, flows into the chamber 232, and acts on the inner end of the main stage valve spool 204. When the pressure in passage 156 increases sufficiently to generate a transient pressure, the force applied to the high pressure end of spool 204 by the oil in high pressure passage 156 is applied to the low pressure end of the spool by spring 208 and oil in chamber 232. Greater than the force, the spool moves to the left as shown in FIG. 9 and opens the cross passage 210, allowing high pressure oil to flow back through the crankshaft to the oil pan 16 and reduce the pressure in the passage 156. .
[0080]
The solenoid force at pilot stage valve 195 is counteracted by the oil pressure in chamber 232 acting on pin 228 over the area of the opening in seat 200. If the electronic control module requires an increase in pressure in the manifold 24, the current flow to the solenoid 220 increases to allow the pilot flow of oil to the engine oil pan through the valve 195, orifice 219, and then the shaft. To reduce. The decrease in pressure in chamber 125 allows spring 120 to move spool 112 toward the open position as shown in FIG. Oil released from chamber 125 flows through passage 124 to chamber 216, through orifice 219, and through the crankshaft to the engine oil pan.
[0081]
Moving the spool 112 toward the open position increases the flow port leading to the crank chamber and correspondingly increases the amount of oil that flows into the crank chamber and is pumped into the manifold 24 by the high pressure poppet valve pump. . The inlet throttle valve opens at a speed determined by the force acting on the spool 112. The oil pressure in the bore 106 acting on the spool area and the spring 120 urges the spool toward the open position. These forces act on the area of the spool and are resisted by the oil pressure in the chamber 125 that represses the spool in the opposite direction. The spool moves toward the open position until force balance or balance position is achieved. Once the equilibrium position of the spool is achieved, the pilot flow rate through the outflow passage 219 is too low to move the spool 204 relative to the spring 208 and provide sufficient differential pressure across the orifice 205 to open the valve 194. It cannot be generated. Increasing the flow of oil pumped into the manifold increases the oil pressure in the manifold.
[0082]
When the solenoid current increases, the valve 194 will remain closed if the main stage IPR valve 194 is closed. If the main stage valve 194 is partially open, the solenoid current increases to partially close the valve 195, increase the pressure in the chamber 232, and close the valve 194.
[0083]
As the oil pressure in the manifold 24 increases, the pressure in the chamber 232 increases and the pilot flow through the passage 219 resumes, resulting in a pressure increase in the chamber 125 that stops the inlet throttle spool opening movement. If the inlet throttle spool goes too far into the equilibrium position and the oil pressure in the manifold exceeds the commanded level, the main stage IPR valve 194 opens, allowing oil to flow out of the manifold and commanding the pressure in the manifold. Lower to the desired level.
[0084]
A rapid decrease in solenoid current can reduce the force that urges the valve pin 228 toward the seat 200 to rapidly increase pilot flow and flow to the inlet throttle valve chamber 125. Increasing pressure at the closed end of the spool moves the spool in the closing direction, i.e., to the left as shown in FIG. 12, reducing oil flow to the crank chamber. The pumping chamber is not completely filled and the amount of high pressure oil entering the manifold is reduced.
[0085]
The response of the inlet throttle can be delayed from a gradual decrease in solenoid current due to the time required to consume oil in the crankcase as the solenoid current decreases. In this case, opening the pilot valve 195 reduces the pressure in the chamber 232 and opens the main stage IPR valve 194 to allow a restricted flow from the manifold to the oil pan so that the oil pressure in the manifold can be reduced. To.
[0086]
During balanced operation of the diesel engine, the solenoid 220 receives an essentially constant amperage signal, and the pilot oil flows through the valve 194 uniformly through the orifice 219 to the chamber 214, but with pressure due to injection and piston pulsation. Affected by fluctuations. The resulting pressure in chamber 125, delivered by passage 124, acts on the closed end of spool 112 and is resisted by the force of spring 120 and the inlet pressure acting on spool 112. A force balance occurs, so that the oil flow to the crankcase is sufficient to maintain the desired pressure in the manifold 24.
[0087]
The pump assembly 10 controlled by the inlet throttle valve flows the required amount of engine oil to the manifold 24 over the diesel engine operating range to meet the requirements of the HEUI injector. During start-up, when the engine is cranked by the starter, the inlet throttle valve is fully opened and the high pressure check Valve The pump 74 at full capacity increases the oil pressure in the manifold to the engine starting pressure. While the engine is idling at a low speed of about 600 rpm, the inlet throttle valve spool moves to the closed position, where only the flow control openings 134b, 136a, and 136b are partially open, 42 kilograms per square centimeter. A low amount of oil is pumped to maintain a low manifold idling pressure (600 pounds per square inch). If the minimum flow rate allowed by the inlet throttle spool is not utilized by the injector, the main stage IPR valve 194 opens to allow excess oil to return to the oil pan.
[0088]
The pump assembly 10 flows high pressure oil to the manifold 24 and, if provided, to the compression chamber 26. The high pressure oil is sufficiently compressed so that the flow requirements of the injector 12 are satisfied by the expansion of the oil. The flow rate requirements of the injector vary depending on the electrical activation signal or the duration of the injection process of the injector. The control module may change the timing of the injection process relative to the top dead center of the engine piston according to the desired operating parameters of the engine. A large amount of oil compressed by the pump assembly 10 will always provide a sufficient amount of compressed oil for expansion whenever the injection process is performed regardless of the timing of the injection process signal. to be certain.
[0089]
Large capacity manifolds and compression chambers increase the cost of diesel engines. Many enough to provide a high pressure pumping stroke during the execution of each injection step for each engine cylinder piston By providing the HEUI pump assembly 10 with the pump 74 in the diesel engine, the capacity of the internal manifold can be reduced and the external chamber can be eliminated. For example, the pumping stroke of each high-pressure pump has a sufficient amount of high-pressure oil in the pressure line connected to the injector so that a sufficient amount of pressurized oil is obtained to activate the injector when injection is performed. Can be timed to flow in. For example, the pump assembly 10 has four pumping strokes each having a pumping stroke of about 180 degrees so that a sequential stroke occurs during each rotation of the crankshaft 40. piston A pump 74 is included. The pump assembly is mounted on an 8-cylinder diesel engine by timing the rotation of the crankshaft of the pump assembly so that the output flows into the pipes connected to the peak of the injector when each injector is started. Can do. In this way, it is possible to provide a sufficient amount of flow pulses in the piping to activate the injector at the proper time without the need for a large volume manifold or compression chamber. In other four-stroke cycle engines, one high pressure pump can pump oil during the injection process for each pair of cylinders.
[0090]
The control pump assembly 10 includes a hydraulic system including an inlet throttle valve and an electrically modulated valve 195 for controlling the inlet throttle valve to throttle the flow rate of oil at the inlet to the pump assembly 241 shown in FIG. Including. If desired, the hydraulic regulator may include a fast response pressure transducer mounted on the high pressure outlet passage 156 to generate a signal proportional to the pressure in the passage, an output signal from the pressure transducer, and a desired pressure in the high pressure passage. Can be replaced by an electrical regulator that includes a comparator that receives a signal from a diesel engine electronic control module proportional to the pressure of the engine and generates an output signal proportional to the difference between the two signals. The electrical system is also typically a proportional solenoid for moving the spool of the inlet throttle valve to increase or decrease the flow of oil to the pump assembly 241 as necessary to increase or decrease the pressure in the high pressure passage. Includes certain electrical actuators. The electrical control system includes a pressure relief valve similar to valve 194 and a mechanical relief valve similar to valve 168 that causes oil to flow from passage 156 in response to the transient pressure. The electrical regulator controls the output pressure as described above.
[0091]
Pump assembly 10 is useful in maintaining the desired pressure of oil flowing to the diesel engine HEUI injector. However, the assembly can also be used for various applications. For example, the pump may rotate at a constant speed, and an inlet throttle valve may be used to control the pump to flow liquid at various flow rates determined by the position of the throttle valve spool. The spool can be adjusted manually or by an automatic adjuster. The pumped liquid can flow without any restriction or can be pumped into a closed chamber by the chamber pressure determined by the flow rate from the chamber.
[0092]
While the inventor of the present invention has shown and described the preferred embodiment of the present invention, it will be understood that the present invention is amenable to modification and therefore, the inventor will not be described in the exact details described herein. While not wishing to be limited, it is desired that the present invention include modifications and alternatives that fall within the scope of the claims.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a pump assembly, a pressure chamber, and an injection device.
FIG. 2 is a side view of the pump assembly.
3 is a view taken along line 3-3 in FIG. 2, respectively.
4 is a view taken along line 4-4 of FIG. 2, respectively.
5 is a view taken along line 5-5 of FIG. 2, respectively.
6 is a cross-sectional view taken along line 6-6 of FIG.
7 is a cross-sectional view taken along line 7-7 of FIG. 3, respectively.
8 is a cross-sectional view taken along line 8-8 of FIG.
9 is a cross-sectional view taken along line 9-9 of FIG.
FIG. 9a is an enlarged view of a part of FIG.
10 is a cross-sectional view taken along line 10-10 in FIG.
11 is a cross-sectional view taken along line 11-11 in FIG.
12 is a cross-sectional view taken along line 12-12 of FIG.
FIG. 13 is a side view of the spool of the inlet throttle valve.
FIG. 14 is a drawing of the surface of the released throttle valve spool;
14a is a cross-sectional view taken along line 14a-14g of FIG. 13 showing the position of the circumferential flow opening.
FIG. 15 is a diagram of a hydraulic circuit of a pump assembly.
FIG. 16 is a drawing showing a manufacturing process of the first check valve assembly;
FIG. 17 is a drawing showing a manufacturing process of the first check valve assembly.
FIG. 18 is a drawing showing a second check valve assembly and its manufacturing process.
FIG. 19 is a drawing showing a second check valve assembly and its manufacturing process.

Claims (9)

A pump assembly whose output is controlled, wherein the main body (28), the crank chamber (36) in the main body (28), and the main body (28) are rotatably attached to the crank chamber ( 36) a shaft (40) including a drive end and an eccentric member (52), a piston bore (76) in the main body (28) and opening into the crank chamber (36), and the crank An outlet check valve assembly (90) communicating with the piston bore (76) in a direction away from the chamber (36) and extending from the outlet check valve assembly (90) to an outlet port (22). A high pressure outlet passageway (152, 154) and a piston (78) movable through the piston bore (76) over a pumping stroke and a return stroke, adjacent to the crank chamber (36) A piston (78) having an end (80) and a piston passage (84) extending therethrough, wherein the piston and the piston bore define a variable volume pumping chamber (88); A slipper (82) positioned between a piston end (80) and the eccentric member (52), the first surface engaging the eccentric member, and engaging the piston end. A slipper including a second surface and a central passageway (84) extending between the first surface and the second surface; and a recess (58) in the eccentric member, the The central passage (84) overlaps the recess (58) during the return stroke and communicates with the recess to allow fluid to flow, and the central passage (84) is closed during the piston pumping stroke. And the flow at the entrance to the pumping chamber An inlet throttle valve (104) including a movable valve spool (112) for controlling the pressure, a regulator (192) for moving the valve spool (112) in response to variable parameters, and a return of the piston (78) During the stroke , the inlet throttle valve (104) communicates with the crank chamber (36) and the pumping chamber (88) via the recess (58) and the central passage (84) of the eccentric member (52). ) and a configured inlet passage so as to communicate (110), between the port down ping stroke of the piston is controlled by the output pressure of the pump assembly regulator includes an inlet passage that is closed (110) A pump assembly characterized in that: A pump assembly for pressurizing fluid used to operate an electronically controlled device in an internal combustion engine having an electronic control module, wherein the regulator (192) is at a desired pressure in the outlet passage. solenoid control valve for providing fluid flow to the valve member of the inlet throttle valve receive a second signal proportional to the actual pressure in the outlet passage with receiving a first signal proportional from the electronic control module (195) And when the pressure in the outlet passage is less than or equal to the desired pressure in the outlet passage, the fluid flow from the regulator (192) moves the valve member to open the inlet throttle valve and to pump the pumping Increasing the amount of fluid flowing into the chamber, closing the inlet throttle valve when the pressure in the outlet passage is greater than or equal to the desired pressure in the outlet passage; Pump assembly according to claim 1 which reduces the amount of fluid flowing into the serial pumping chamber and said and Turkey. Includes a plug (96) at the end of the piston bore, a poppet disc (98) is located in the piston bore, and the outlet passage opens into the piston bore between the poppet disc and the plug. The pump assembly according to claim 1 or 2.   The pump assembly according to any one of claims 1 to 3, wherein the inlet passage extends through the crank chamber (36).   5. The pump assembly according to claim 1, wherein the rotation of the eccentric member opens the inlet passage after the start of each return stroke of the piston.   The inlet throttle valve (106), a spool (112) movable in the throttle bore between an open position and a closed position; and an inlet throttle valve spring that resiliently pressurizes the spool toward the open position. (120) The pump assembly according to any one of claims 1 to 5, characterized in that The spool includes a wall and a plurality of flow control ports (130-136), the plurality of flow control ports extending through the wall and spaced apart from each other along the wall. A pump assembly according to claim 1. Pump assembly according to claim 7, wherein the plurality of flow control openings are slightly larger offset than 1/4 of the diameter for each other. 9. A pump assembly as claimed in claim 7 or 8, wherein the flow control ports include opposing pairs of openings.

Images